Overview
Horner & Shifrin was contracted by Ameren Illinois to provide floodplain permitting assistance with St. Clair County for aging tower replacement in unincorporated portions of their jurisdiction. The utility company is replacing aging infrastructure with more modern mono-poles along various waterways. Ameren required assistance providing a hydraulic analysis of the Mississippi River and a no-rise certification for their proposed work within the floodway to prove a no-rise condition. In addition to County permitting, H&S worked with the City of East Carondolet and the Illinois Office of Water Resources for permitting compliance and approvals.
Flood analysis included acquiring the existing HEC-2 river models and importing and developing HEC-RAS models for the duplicate effective, corrected effective, existing, and proposed conditions. Because no existing models were available through FEMA, the US Army Corps of Engineers, the County, City, or State, the models were created from scratch to best fit the output files obtained by FEMA for the Mississippi River. Floodplain analysis reports, Floodplain Development Permit Applications, and No-Rise Certificates will be provided upon analysis completion to both the City of East Carondolet, St. Clair County, and the Office of Water Resources.
